Search results for "Frontal Lobe"
showing 10 items of 158 documents
The effect of age on cognitive performance of frontal patients
2015
Age is known to affect prefrontal brain structure and executive functioning in healthy older adults, patients with neurodegenerative conditions and TBI. Yet, no studies appear to have systematically investigated the effect of age on cognitive performance in patients with focal lesions. We investigated the effect of age on the cognitive performance of a large sample of tumour and stroke patients with focal unilateral, frontal (n=68), or non-frontal lesions (n=45) and healthy controls (n=52). We retrospectively reviewed their cross sectional cognitive and imaging data. In our frontal patients, age significantly predicted the magnitude of their impairment on two executive tests (Raven's Advanc…
Physical Activity Predicts Population-Level Age-Related Differences in Frontal White Matter
2018
Physical activity has positive effects on brain health and cognitive function throughout the life span. Thus far, few studies have examined the effects of physical activity on white matter microstructure and psychomotor speed within the same, population-based sample (critical if conclusions are to extend to the wider population). Here, using diffusion tensor imaging and a simple reaction time task within a relatively large population-derived sample (N = 399; 18–87 years) from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN), we demonstrate that physical activity mediates the effect of age on white matter integrity, measured with fractional anisotropy. Higher self-reported daily ph…
Cognitive reserve and cognitive performance of patients with focal frontal lesions.
2016
The Cognitive reserve (CR) hypothesis was put forward to account for the variability in cognitive performance of patients with similar degrees of brain pathology. Compensatory neural activity within the frontal lobes has often been associated with CR. For the first time we investigated the independent effects of two CR proxies, education and NART IQ, on measures of executive function, fluid intelligence, speed of information processing, verbal short term memory (vSTM), naming, and perception in a sample of 86 patients with focal, unilateral frontal lesions and 142 healthy controls. We fitted multiple linear regression models for each of the cognitive measures and found that only NART IQ pre…
Auditory event-related potentials over medial frontal electrodes express both negative and positive prediction errors
2015
International audience; While the neuronal activation in the medial frontal cortex is thought to reflect higher-order evaluation processes of reward prediction errors when a reward deviates from our expectation, there is increasing evidence that the medial frontal activity might express prediction errors in general. However, given that several studies examined the medial frontal event-related potentials (ERPs) by comparing signals triggered by different stimuli and different anticipations, it remains an open question whether the medial frontal signals are sensitive to the valence of prediction errors. Here we orthogonally manipulated expectation magnitude (i.e., large/small expectation) and…
Shape analysis of the cingulum, uncinate and arcuate fasciculi in patients with bipolar disorder
2016
Background: Abnormal maturation of brain connectivity is supposed to underlie the dysfunctional emotion regulation in patients with bipolar disorder (BD). To test this hypothesis, white matter integrity is usually investigated using measures of water diffusivity provided by MRI. Here we consider a more intuitive aspect of the morphometry of the white matter tracts: the shape of the fibre bundles, which is associated with neurodevelopment. We analyzed the shape of 3 tracts involved in BD: the cingulum (CG), uncinate fasciculus (UF) and arcuate fasciculus (AF). Methods: We analyzed diffusion MRI data in patients with BD and healthy controls. The fibre bundles were reconstructed using Q-ball–b…
Impaired regulation of emotion: Neural correlates of reappraisal and distraction in bipolar disorder and unaffected relatives
2015
Deficient emotion regulation has been proposed as a crucial pathological mechanism in bipolar disorder (BD). We therefore investigated emotion regulation impairments in BD, the related neural underpinnings and their etiological relevance for the disorder. Twenty-two euthymic patients with bipolar-I disorder and 17 unaffected first-degree relatives of BD-I patients, as well as two groups of healthy gender-, age- and education-matched controls (N=22/17, respectively) were included. Participants underwent functional magnetic resonance imaging while applying two different emotion regulation techniques, reappraisal and distraction, when presented with emotional images. BD patients and relatives …
IQ and the fronto-temporal cortex in bipolar disorder.
2012
AbstractCognitive changes are documented in bipolar disorder (BP). Cortical volume loss, especially in prefrontal regions, has also been reported, but associations between cognition and cortical abnormalities have not been fully documented. This study explores associations between cognitive performance and cortical parameters (area, thickness and volume) of the fronto-temporal cortex in 36 BP patients (25 BPI and 11 BPII). T1-weighted volumetric MRI images were obtained using a 1.5 Tesla scanner. Cortical parameters were measured using surface-based morphometry and their associations with estimated premorbid, current IQ, visual memory, and executive function explored. Premorbid IQ was assoc…
Cognitive functioning after medial frontal lobe damage including the anterior cingulate cortex: A preliminary investigation
2006
Two patients with medial frontal lobe damage involving the anterior cingulate cortex (ACC) performed a range of cognitive tasks, including tests of executive function and anterior attention. Both patients lesions extended beyond the ACC, therefore caution needs to be exerted in ascribing observed deficits to the ACC alone. Patient performance was compared with age and education matched healthy controls. Both patients showed intact intellectual, memory, and language abilities. No clear-cut abnormalities were noted in visuoperceptual functions. Speed of information processing was mildly reduced only in Patient 2 (bilateral ACC lesion). The patients demonstrated weak or impaired performance on…
Development and validation of a reliable method for studying the distribution pattern for opiates metabolites in brain
2012
Abstract Brain distribution pattern of “street” heroin metabolites (morphine and codeine) was investigated in two fatalities due to “acute narcotism”. A suitable sample pretreatment prior to solid-phase-extraction was developed to achieve a good recovery of the analytes and to eliminate the interfering species. After derivatization with MSTFA, samples were analyzed by GC/MS. Specificity, accuracy, precision and linearity of the method were evaluated; LOD and LOQ were, respectively, 10 ng/25 ng for morphine and 5 ng/10 ng for codeine. This method was applied to the analysis of six brain areas (hippocampus, frontal lobe, occipital lobe, nuclei, bulb and pons) coming from two cases of heroin-r…
Does the left inferior parietal lobule contribute to multiplication facts?
2005
We report a single case, who presents with a selective and severe impairment for multiplication and division facts. His ability to retrieve subtraction and addition facts was entirely normal. His brain lesion affected the left superior temporal and to lesser extent in the left middle temporal gyri and the left precentral gyrus extending inferiorly to the pars opercularis of the left frontal lobe. Interestingly, the left supramarginal and angular gyri (SMG/AG) were spared. This finding realised a double dissociation with a previously reported patient, who despite lesions in the SMG/AG did not have a multiplication impairment (van Harskamp et al., 2002). The previously suggested crucial role …